In industrial settings valves often have to be located overhead and out of reach of workers. In order to open and close these valves they are equipped with a chain wheel valve operator sometimes referred to as a chain wheel. This is a wheel interconnected with the valve stem. A chain loop runs over the wheel and engages with the wheel. The chain also hangs down low enough so that it is within reach of a worker standing on the ground below the valve. The worker can then turn the wheel and operate the valve by pulling on one side of the chain or the other. This allows the worker to open or close the valve depending on which side of the chain loop they are pulling on.
One of the requirements for industrial facilities is to be able to lockout all sources of energy to a system prior to working on the system, commonly known as “lockout tagout”. This includes locking out electrical as well as hydraulic and pneumatic power sources. It also requires the ability to stop the flow of liquids and gases that might be processed in the system. If these items are not locked out, another worker may come into the area and turn on one of these power sources or open the flow of one of these liquids or gases. This could result in severe bodily injury or even death of the worker working on the system.
As can be imagined, locking out a valve operated by a chain wheel can be difficult. The wheel and valve are located out of reach of the worker. Thus it would be necessary to climb up to the valve or chain wheel to lock it out directly. The other option would be to somehow lock up the loop of chain hanging into the reach of the worker. Aside from locking the chain to a fixed structure, locking the chain by itself is difficult. For this reason other devices for immobilizing the chain are found in the prior art. However these tend to be large and rather cumbersome devices.
What is needed is a compact efficient device to lockout and tagout these chain wheels.